The invention relates to an apparatus for forming a dead, short or waste winding before the production of a reserve winding when winding a thread onto a spool or the like. The thread is fed from a delivery mechanism via a changeover or traversing device to the spool. The start or end of the thread is inserted into an entrainment device such as a notch or groove formed in the spool.
It is known to expose the thread to a short duration deviation by forming a loop therein during the time while the thread is in an untensioned condition. This occurs when the end of the thread is initially secured to the end location of the spool. Specific reference is made to my copending application, Ser. No. 413,738 filed Nov. 7, 1973. This known assembly is effective to keep the thread under a constant tension during the insertion thereof onto the spool. The formation of this loop which may be by a stream of air from a blowing device maintains the appropriate amount of tension during the time that the thread tangentially encounters a means for forming a reserve winding on the spool until the thread has been brought up to the thread guide of the traversing device. At that time, the thread catches on the thread guide of the self-threading traversing device. Consequently, the thread is automatically transferred to the traversing device upon being fixed to the spool via the formation of a reserve winding.
The reserve winding forming mechanism includes a rotatably mounted worm which is tangentially engaged by the thread. The thread is transported by the worm and automatically guided over the width of the reserve winding area on the spool and brought into the region of the thread guide of the traversing device at the outlet side of the worm.
Stretchable threads, that is, threads which are only partly prestretched when arriving at the winding stage, are now frequently wound. The final stretching of the threads is only effected during texturizing when the heat generated at this stage can also be utilized. When such partially stretched threads are applied to the spool, i.e. are inserted into a notch or groove in an end location of the spool, it is unavoidable that they will be stretched slightly further. The degree of this further stretching is uncontrollable at the beginning of the winding process. Greater or lesser jolts or shocks can be experienced by the thread to be wound. Thus, the thread undergoes different tensions thereby giving rise to different degrees of partial stretching of the thread. Such a thread is unsuitable for any practical use. It has been found that the varying partial stretching of the thread has an effect on further processing. For example, the physical condition of the thread has an effect on the dyeing process thereby causing adverse effects on the finished product. It is therefore desirable that the initial length of thread wound onto the spool and which is subjected to uncontrollable tensions, can be easily eliminated during the later use of the thread spool. It is desirable that a significant and usable portion of a reserve winding incorporate normal conditions of constant thread tension so that the thread may be usable for later processing.